Simó J., Romero del Castillo R., Almirall A., Casañas F. ‘Roquerola’ and ‘Montferri’, First Improved Onion (Allium cepa L.) Cultivars for ‘Calçots’ Production. HortScience. Vol. 47no. 6 801-802.
“Calçots” are the floral stem of second-year onion resprouts of the ‘Blanca Tardana de Lleida’ onion landrace. These resprouts are harvested during winter (December to April) when they reach the commercial size for consumption, i.e., when the edible white part is ≈200 mm long and 25 mm in diameter. Each onion yields between one and 20 “calçots,” and their thickness is negatively correlated with the number of “calçots” per onion, i.e., plants with a high number of resprouts yield few, if any, commercial “calçots.” In the field management, all the resprouts from an onion are harvested at the same time, when 50% or more reach the commercial size indicated as specified in the regulations for the ‘Calçot de Valls’ Protected Geographical Indication (http://www.gencat.cat). This particular use of the onion is typical of Catalonia (northeast Spain), where “calçots” are usually grilled or roasted. The tradition dates from the 1930s and has recently started to spread to other regions in Spain and other countries; the current market volume is ≈20 million Euros and is quickly rising. Traditionally producers have used local populations of the landrace and no breeding programs had been undertaken (Muñoz et al., 2003), resulting in large differences in the yield of commercial “calçots” per plant and low total yields.
Compared with previously existing populations, the two new cultivars obtained, ‘Roquerola’, an early cultivar, and ‘Montferri’, a late cultivar, significantly increase the mean number of commercial “calçots” obtained from each plant while maintaining the sensory characteristics. The combined use of these two cultivars makes it possible to begin the growing season earlier and maintain production throughout the winter, when the demand is highest.